Considering the problems existing in prefecturelevel TV weather forecast program making, with the VB programming tool and the reflectivity factor data from newgerenration radar, a TGA document series with an Alpha channel is generated, by means of the cubic convolution interpolation algorithm scaling. The TGA document series can be broadcasted by most nonlinear editing software. The background pictures and the video frequency can be added through the Alpha channel. The radar products can be broadcasted in TV weather forecast programs. It indicates that the interpolation precision of the cubic convolution resampling method, as well as the colour continuity and picture quality, is satisfactory. The pictures accord the broadcast standards and the high frequency component can be retained well.